Kaplan Maternity Practice Exam 2025 – Complete Prep Guide

The tonic neck reflex typically disappears by 3 to 4 months of age, making it the correct answer. This reflex occurs when a newborn turns their head to one side, causing the arm on that side to extend while the opposite arm bends at the elbow. It is a primitive reflex that is present at birth and is thought to aid in the development of motor skills and coordination.

As infants grow and develop, their nervous system matures, and many of these reflexes fade or are integrated into more complex motor patterns. The disappearance of the tonic neck reflex is a normal part of neurological development and indicates progress in the infant's muscle control and coordination.

The other options do not disappear until later. The stepping reflex, for instance, may persist longer as it is linked to early walking patterns, while the palmar grasp reflex usually diminishes around 5 to 6 months as hand control improves. Babinski's sign, involving the fanning of the toes when the sole of the foot is stroked, typically disappears around 12 months, as it indicates maturation of the nervous system. Thus, the timing of the tonic neck reflex's disappearance is a key marker in assessing infant development.